Movable device for rolling road surfaces and the like



Sept. 19, 1961 B. KALTENEGGER 3,000,278

MOVABLE DEVICE FOR ROLLING ROAD SURFACES AND THE LIKE Filed Nov. 21, 1958 2 Sheets-Sheet 1 Ila Ila

K Z INVENTO/P B. a tene er By 59 Sept. 19, 1961 B. KALTENEGGER 3,000,273

MOVABLE} DEVICE FOR ROLLING ROAD SURFACES AND THE LIKE Filed NOV. 21, 1958 2 Sheets-Sheet 2 INVEVTOR B Ka/tenegger United States Patent 3,000,278 MOVABLE DEVICE FOR ROLLING ROAD SURFACES AND THE LIE Benn'o Kaltenegger, Siegburg-Bnisdorf, Germany, assignor to Bomag Bopparder Maschinenbaugesellschaft m.b.H-,

Boppard, Germany, a firm Filed Nov. 21, 1958, Ser. No. 775,532 Claims priority, application Germany Nov. 23, 1957 5 Claims. (Cl. 94-50) This invention relates to a movable device for rolling road surface courses, aggregate and similar bases, said device being in form of a road roller having two weightloaded running wheels arranged one after the other in the direction of motion.

More particularly, the invention relates to a device of the type mentioned, the two running wheels of which, while the device is moved, are under the constant action of unbalance forces causing an uninterrupted change of the total load of each running wheel, the load of each wheel changing according to a sine-shaped curve, i.e. from a maximum value through a minimum value and back to the maximum value. By an appropriate arrangement of the unbalances, there is always acting on the one running wheel a component of force directed in upward direction and on the other running wheel a component of force directed downwardly at any one time. The consequent constant change of load on the two running wheels has a surprisingly favorable efiect on the work to be performed by the device.

The periods of the sine-shaped load curves are capable of being extended or shortened by varying the speed of rotation of the unbalances. The amplitude of the load curves depends only upon the unbalance mass itself, i.e., upon its weight. A change of the amplitude can be brought about by replacing the unbalances by unbalances of greater or smaller mass. However, this can be made only with a relatively great expense of time and work. A fine adjustment of the variations of amplitude would require a correspondingly extensive inventory of unbalance sets of various masses.

It is an object of the present invention to provide a further improvement and embodiment of the device for varying the amplitude of the sine-shaped load curves of the running wheels without any interchange of unbalances. It is characterized in that at least one driven horizontal shaft is journalled with its ends at the chassis of the device above the running wheels, said shaft extending in the direction of travel of the rolling device and bearing two unbalances which are shiftable in this direction and staggered by 180 degrees with respect to each other.

The vertical components of force produced by the rotating unbalances impart to the unbalance shaft a pendulum motion about an imaginary axis extending parallel to the axes of rotation of the running wheels. The pendulum motion of the unbalance shaft transmits itself through the chassis and to the trunnions of the running wheels. Due to the staggered arrangement of the unbalances, an impulse directed in upward direction is always acting at any one time on the one running wheel and an impulse directed in downward direction is always acting at any one time on the other running wheel. The amplitude of the pendulum motion of the unbalance shaft and consequently also the amplitude of the sine-shaped load curve of the running wheels is dependent upon the adjustable distance of the unbalances, the adjustment being capable of being made continuously. The greater the distance between the unbalances, the greater will be the respective amplitudes.

When only one unbalance shaft is provided, the horizontal components of force produced by the same will also act through the chassis upon the running wheels, forcing on them a pendulum motion longitudinally of their axes of rotation. Such a pendulum motion is undesirable in many cases and can be avoided in a simple manner in accordance with a further development of the invention. This further development ischaracterized in that two unbalance shaft assemblies are provided in such a manner that the two unbalance shafts which, by a gear, are made to run in opposite directions of rotation, are arranged symmetrically and parallel to the longitudinal center line of the rolling device and the front as well as the rear unbalances of said shafts are coupled in pairs, each of which pairs is shiftable in the direction of travel of the roller. The horizontal components of force produced by the unbalances of each pair constantly counterbalance each other irrespective of the distance between the two unbalance pairs. However, since the unbalances at opposite ends of each shaft are disposed 180 degrees out of phase and since the unbalances of each pair are in phase vertically, it will be seen that during the rotation of the unbalances, the forces exerted by the unbalances on the chassis in a vertical direction will be opposite to each other to impart a rocking movement to the chassis about a transverse center line of the chassis. When the unbalances of one pair are disposed in an upwardly directed vertical direction, the unbalances of the other pair will be disposed in an opposite depending position.

Further features of the invention are explained in greater detail with reference to an embodiment shown in the appended drawing where, in partially simplified manner of representation,

FIG. 1 is a front view of a device for rolling road surface courses and the like,

FIG. 2 is a vertical sectional view of the device along the line 2-2 of FIG. 1, and 1 FIG. 3 is a horizontal sectional view through the device along the line 3-3 of FIG. 2, and

FIG. 4, on an enlarged scale, is a vertical cross-sectional view along the line 4-4 of FIG. 2.

Referring to the drawing, the chassis 11 of a device for rolling road surface courses, aggregate and similar road bases bears pairs of lateral end pieces 11a wherein weight-loaded running wheels 12 of conventional construction are arranged one after the other in the direction of travel. The device may be a self-propelled roller provided with appropriate drive means for the wheels 12 or be constructed as a trailer to be moved by a tractor or the like.

Pivotally mounted with their ends on the chassis 11 and symmetrically to the longitudinal center line thereof are two ribbed shafts 13 and 13a connected by a gear 14. The shaft 13 is driven by a belt drive 15 or the like by means of a motor 16 and, via the gear 14, takes the other shaft 13a along in rotation in opposite direction. Each of the shafts 13 and 13a bears a pair of unbalances or weights 17 and 18 staggered by degrees, said unbalances being non-rotatable relative to the respective shaft but are shiftable in longitudinal direction of the respective shaft. The front and rear unbalances 17, 17a and 18, 18a of the shafts 13, 13a are coupled in pairs with each pair at opposite ends of the chassis being in opposite phase when in vertical position. In the embodiment shown, this is realized in a manner that each unbalance 17, 17a or 18, 18a is fixedly and, if desired, replaceably fastened to a cylindrical hub 19 which in turn is fixedly fastened on the associated shaft 13, 13a

against relative rotation and is shiftable in longitudinal engaging the hubs, does not impede their rotation as will be understood from an inspection of FIGS. 2 and 4. The web plates 20 each has an internally threaded opening therein that threadably receives the adjacent end of the shaft or spindle 22, the opposite ends of which spindle 22 are oppositely threaded as at 22a and 22b as illustrated in FIG. 3 for actuation by the spindle 22 with the masses or unbfl-ances 17, 17a and 18, 18a shifted in opposite direction with respect to each other in the direction of travel of the roller, said shifting being efiected by means of the threaded spindle 22 actuated by a crank handle 21.

, As may be seen from the drawing, both the front pair of unbalances 17, 17a and the rear pair of balances 18, 18a are fastened to the associated shafts 13 with the unbalances of respective pairs being in transverse alignment and in phase vertically but 180 degrees out of phase horizontally. Consequently, the horizontal components of force produced by the cooperating unbalances of the front and rear pairs of unbalances will always counter balance each other. On the other hand, the front pair of unbalances are 180 degrees out of phase vertically and produce alternating vertical force components at opposite ends of the shafts to produce a vertical rocking movement about a transverse center line through the chassis 11. By shifting the unbalance pairs 17, 17a and 18, 18a in longitudinal direction of the shafts 13, 13a and in opposite direction with respect to each other, the amplitude of the pendulum motions of the shafts 13, 13a which transmit themselves to the running wheels 12 in the manner described above can be varied continuously as desired within the shortest possible time by simply turning the crank handle 21. The maximum value of the oscillation amplitude is dependent upon the mass of the unbalance pairs 17, 17a and 18, 18a. These unbalance pairs are arranged at easily accessible places and, therefore, can be conveniently interchanged if required with other unbalances of greater or smaller masses.

It is, however, possible within the limits set by the unbalance masses to adjust in most simple manner the amplitude of the sine-shaped load curves of the running wheels 12 at any intermediate value desired. By appropriate arrangement and design of the spindle drive 21, 22, the unbalances 17a, 17 and 18, 18a, i.e. the unbalance pairs 17, 17a and 18, 18a, are preferably always at equal distances from an imaginary vertical cross plane extending through the chassis 11 in the middle between and parallel to the axes of rotation of the wheels 12. In this embodiment of the invention, the vertical unbalance forces acting upon the front wheel and those acting in opposite direction on the rear wheel are always equal in amount.

I claim:

1. A vehicle for rolling road surfaces having two weight-loaded running wheels arranged one after the other in the longitudinal direction of travel, the axles of said wheels being subject to constant vibratory action of eccentric masses rotating in a vertical plane, a pair of power driven shafts extending longitudinally of said vehicle and journaled at opposite ends on the chassis thereof above said wheels, means coupling together and driving said shaftis for rotation in opposite directions, said shafts non-rotatably supporting pairs of eccentric masses shiftable longitudinally on said shafts, the masses on each shaft being located degrees out of phase at all times, said eccentric masses being disposed as pairs substantially equidistant from a central vertical plane through said chassis, and means mounting said eccentric masses for movement on said shafts longitudinally of said chassis to vary the effective moment arms of said eccentric masses.

2. The structure of claim 1; together with force transmitting means operatively connected to said eccentric masses for simultaneously shifting the same relative to said vertical plane to maintain the equidistant relationship.

3. The structure of claim 1; wherein said shafts and eccentric masses are disposed symmetrical and parallel to the longitudinal axis of said vehicle, and said means coupling together and driving said shafts including meshing gears for simultaneously rotating the shafts.

4. The structure of claim 1; wherein the means mounting said eccentric masses for movement on said shafts include each eccentric mass being fixedly mounted on a hub shiftable longitudinally of said shafts, said hubs being connected to a web plate extending transversely of said shafts and interconnecting adjacent pairs of said hubs 5. The structure of claim 4, including 'a spindle shaft extending substantially parallel to said shafts with one end portion thereof having left-hand threads and the other end thereof having right-hand threads, each of said web plates having threaded apertures therein and engaging an end of said spindle shaft, and means to rotate said shaft to simultaneously vary the spacing between said webs thereby increasing or decreasing the moment arm of the vibration forcestransmitted to said wheels.

References Cited in the file of this patent UNITED STATES PATENTS 1,364,605 Ashmore et al. 1 Jan. 4, 1921 1,364,606 Ashmore et a1. Jan. 4, 1921 1,532,843 Stubbs Apr. 7, 1925 2,039,078 Hertwig Apr. 28, 1936 2,133,862, Kerns Oct. 18, 1938. 2,707,559 Saxe May 3, 1955 

